1. Field
Exemplary embodiments of the present invention relate to a method for fabricating a nonvolatile memory device, and more particularly, to a method for fabricating a nonvolatile memory device including an isolation layer.
2. Description of the Related Art
A nonvolatile memory device refers to a memory device which maintains data stored therein even though power supply is cut off. Currently, a variety of nonvolatile memory devices, for example, a NAND-type flash memory and on the like, have been widely used.
Recently, with the increase in integration degree of semiconductor devices, the importance of device isolation technology for electrically isolating adjacent devices has been further increased. A shallow trench isolation (STI) method is typically used as one of device isolation technologies of a semiconductor process and in the STI, a trench defining an active region is formed in a semiconductor substrate, and then filled with a dielectric material to form an isolation layer.
Meanwhile, as the distance between semiconductor devices is reduced, there may be a limitation in increasing the integration degree through the conventional technology which forms only one device in the left and right sides of the isolation layer having an STI structure. Furthermore, as the aspect ratio of the trench increases, a burial characteristic may be degraded. For example, a void may occur in the STI structure.